Polysaccharides are known to have various effects on the organism. Of these, β-glucans are known to bind to receptors (e.g., Dectin-1) and the like existing in immune cells in the organism to activate immunoreaction (see Non Patent Document 1). Although immunopotentiators utilizing the immunopotentiating effect of β-glucans have been researched and developed (see Patent Document 1), the immunopotentiating effect of β-glucans cannot be said to be potent, and concomitant use with other immunopotentiators to obtain sufficient effects has been investigated (see Patent Document 2).
Meanwhile, polysaccharides are also known as the materials of biocompatibility, and they are used as the bases of hydrogel or sustained release materials by utilizing the biocompatibility of polysaccharides. Modification of biodegradable polymers to polysaccharides can transform the physical properties while maintaining the biocompatibility (see Patent Document 3 and Non Patent Document 2).